As global security concerns continue to grow, fingerprint scanning for identity verification is becoming an often used tool for identity verification. Existing fingerprint imaging methods are energy inefficient and require careful calibration. Heretofore, several unsuccessful attempts have been made to address these shortcomings.
U.S. Pat. Nos. 7,519,204, 7,231,078, 6,741,729, 6,125,192, and 6,097,035 disclose a method and apparatus for fingerprint recognition.
U.S. Pat. No. 6,512,381 discloses a fingerprint sensing circuit.
U.S. Pat. No. 5,864,296 discloses a fingerprint ridge, sensor-based detector.
U.S. Pat. No. 7,864,992 discloses a fingerprint sensor element that measures sensor point capacitance.
U.S. Pat. Nos. 6,643,389, 6,580,816, and 6,317,508 disclose a capacitive semiconductor array for fingerprint detection.
U.S. Pat. No. 6,633,656 discloses a fingerprint sensor comprised of an array of microthermistor devices which convert temperature conditions into electrical signals.
U.S. Pat. No. 6,414,297 discloses a fingerprint reading apparatus.
U.S. Pat. No. 4,429,413 discloses a fingerprint sensor for creating an electrical output signal based upon the topological pattern of a finger.
U.S. Patent Application 20050226478 discloses a fingerprint sensor that uses a capacitance detecting circuit.
U.S. Patent Application 20050163350 discloses a fingerprint sensing apparatus.
None of these references, however, teach an energy efficient way to provide accurate fingerprint information without time-consuming calibration.